[Patch v5 14/48] UefiCpuPkg/MpInitLib: Add CPU_VOLATILE_REGISTERS & worker functions


Jeff Fan <jeff.fan@...>
 

Add CPU_VOLATILE_REGISTERS definitions for CRx and DRx required to be restored
after APs received INIT IPI.

Add worker functions SaveVolatileRegisters()/RestoreVolatileRegisters() used to
save/restore CRx and DRx. It also check if Debugging Extensions supported or
not.

v5:
1. Add comment block for structure CPU_VOLATILE_REGISTERS.

Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
---
UefiCpuPkg/Library/MpInitLib/MpLib.c | 71 ++++++++++++++++++++++++++++++++++++
UefiCpuPkg/Library/MpInitLib/MpLib.h | 16 ++++++++
2 files changed, 87 insertions(+)

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 70e5eb1..0832228 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -47,6 +47,73 @@ SetApState (
}

/**
+ Save the volatile registers required to be restored following INIT IPI.
+
+ @param[out] VolatileRegisters Returns buffer saved the volatile resisters
+**/
+VOID
+SaveVolatileRegisters (
+ OUT CPU_VOLATILE_REGISTERS *VolatileRegisters
+ )
+{
+ CPUID_VERSION_INFO_EDX VersionInfoEdx;
+
+ VolatileRegisters->Cr0 = AsmReadCr0 ();
+ VolatileRegisters->Cr3 = AsmReadCr3 ();
+ VolatileRegisters->Cr4 = AsmReadCr4 ();
+
+ AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, NULL, &VersionInfoEdx.Uint32);
+ if (VersionInfoEdx.Bits.DE != 0) {
+ //
+ // If processor supports Debugging Extensions feature
+ // by CPUID.[EAX=01H]:EDX.BIT2
+ //
+ VolatileRegisters->Dr0 = AsmReadDr0 ();
+ VolatileRegisters->Dr1 = AsmReadDr1 ();
+ VolatileRegisters->Dr2 = AsmReadDr2 ();
+ VolatileRegisters->Dr3 = AsmReadDr3 ();
+ VolatileRegisters->Dr6 = AsmReadDr6 ();
+ VolatileRegisters->Dr7 = AsmReadDr7 ();
+ }
+}
+
+/**
+ Restore the volatile registers following INIT IPI.
+
+ @param[in] VolatileRegisters Pointer to volatile resisters
+ @param[in] IsRestoreDr TRUE: Restore DRx if supported
+ FALSE: Do not restore DRx
+**/
+VOID
+RestoreVolatileRegisters (
+ IN CPU_VOLATILE_REGISTERS *VolatileRegisters,
+ IN BOOLEAN IsRestoreDr
+ )
+{
+ CPUID_VERSION_INFO_EDX VersionInfoEdx;
+
+ AsmWriteCr0 (VolatileRegisters->Cr0);
+ AsmWriteCr3 (VolatileRegisters->Cr3);
+ AsmWriteCr4 (VolatileRegisters->Cr4);
+
+ if (IsRestoreDr) {
+ AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, NULL, &VersionInfoEdx.Uint32);
+ if (VersionInfoEdx.Bits.DE != 0) {
+ //
+ // If processor supports Debugging Extensions feature
+ // by CPUID.[EAX=01H]:EDX.BIT2
+ //
+ AsmWriteDr0 (VolatileRegisters->Dr0);
+ AsmWriteDr1 (VolatileRegisters->Dr1);
+ AsmWriteDr2 (VolatileRegisters->Dr2);
+ AsmWriteDr3 (VolatileRegisters->Dr3);
+ AsmWriteDr6 (VolatileRegisters->Dr6);
+ AsmWriteDr7 (VolatileRegisters->Dr7);
+ }
+ }
+}
+
+/**
Detect whether Mwait-monitor feature is supported.

@retval TRUE Mwait-monitor feature is supported.
@@ -204,6 +271,10 @@ MpInitLibInitialize (
CpuMpData->CpuInfoInHob = (UINT64) (UINTN) (CpuMpData->CpuData + MaxLogicalProcessorNumber);
InitializeSpinLock(&CpuMpData->MpLock);
//
+ // Save BSP's Control registers to APs
+ //
+ SaveVolatileRegisters (&CpuMpData->CpuData[0].VolatileRegisters);
+ //
// Set BSP basic information
//
InitializeApData (CpuMpData, 0, 0);
diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h
index 84bd872..ca8bd44 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.h
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h
@@ -66,6 +66,21 @@ typedef enum {
} CPU_STATE;

//
+// CPU volatile registers around INIT-SIPI-SIPI
+//
+typedef struct {
+ UINTN Cr0;
+ UINTN Cr3;
+ UINTN Cr4;
+ UINTN Dr0;
+ UINTN Dr1;
+ UINTN Dr2;
+ UINTN Dr3;
+ UINTN Dr6;
+ UINTN Dr7;
+} CPU_VOLATILE_REGISTERS;
+
+//
// AP related data
//
typedef struct {
@@ -78,6 +93,7 @@ typedef struct {
UINT32 Health;
BOOLEAN CpuHealthy;
volatile CPU_STATE State;
+ CPU_VOLATILE_REGISTERS VolatileRegisters;
BOOLEAN Waiting;
BOOLEAN *Finished;
UINT64 ExpectedTime;
--
2.7.4.windows.1